rafafredd
Well-known member
Man, that´s absolutely beaultiful work. Can´t believe it´s first time DIY. You are a natural! Go for more!
API Mic pre (with Yamaha parts) ***COMPLETED***
- Thread starter khstudio
- Start date
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khstudio
Well-known member
[quote author="rafafredd"]Man, that´s absolutely beaultiful work. Can´t believe it´s first time DIY. You are a natural! Go for more![/quote]
PM2000 Rack Job
http://www.groupdiy.com/index.php?topic=14742&postdays=0&postorder=asc&start=0
PM1000 Rack Job
http://www.groupdiy.com/index.php?topic=14833&highlight=pm1000
LA-2A & 2x GSSL's
http://www.groupdiy.com/index.php?topic=14293&postdays=0&postorder=asc&start=0
Not the First but I am new to a lot of this stuff... I had about 10+ guitar pedals & about 12 tube amps under my belt & felt I was ready to step it up a bit... owning a recording studio and all it can't hurt.
Kevin
PM2000 Rack Job
http://www.groupdiy.com/index.php?topic=14742&postdays=0&postorder=asc&start=0
PM1000 Rack Job
http://www.groupdiy.com/index.php?topic=14833&highlight=pm1000
LA-2A & 2x GSSL's
http://www.groupdiy.com/index.php?topic=14293&postdays=0&postorder=asc&start=0
Not the First but I am new to a lot of this stuff... I had about 10+ guitar pedals & about 12 tube amps under my belt & felt I was ready to step it up a bit... owning a recording studio and all it can't hurt.
Kevin
rafafredd
Well-known member
Oh, not first time, I see. But beaultiful anyway! :thumb:
You gotta test it for yourself. Try polystyrene and mica for these positions. You may be surprised, or may be not.
You could always measure AC current, and then include the right fuse. Let´s say you measure 500mA at 110vAC, use a 1A fuse...
You gotta test it for yourself. Try polystyrene and mica for these positions. You may be surprised, or may be not.
You could always measure AC current, and then include the right fuse. Let´s say you measure 500mA at 110vAC, use a 1A fuse...
khstudio
Well-known member
Thanks Fred,
I just realized you answered my first question earlier in the thread... sorry.
I think my question should have been, is there a preferred cap type in these positions?
The pre sounds very good but each channel has a slightly different shape & character... some better than others. I'm not sure where to begin looking for the differences to get the 2-3 weaker channels up to par :? It's not that they're bad, a few are just a little cloudy & less punchy than the others.
What component(s) do you think have the highest impact on the sound?
The OP-AMP???
I have a few extras of every thing.
Also, when dealing with the feedback cap...
Does the "High End" increase as the caps value goes down?
I ask this because I'm using 47pf Ceramics I pulled from the old board a wondered if some cound be out of spec... I did check them with my volt meters capacitance test setting but I'm sure it's not telling me everything.
This is why I'm asking about the caps... I'm going to place an order for some parts.
Thanks for helping,
Kevin
BTW Fred,
That output drawing looks good & makes sense but I'd like to use ONE output (XLR) for both choices...
Here is the switch I used for my PM2000 to Bypass the Output Tranny BUT an output coupling cap is in the circuit for BOTH positions, just before the switch.(not shown in pic)
I was thinking to use this switch but replace the GREEN wire on TOP Right going from pin to pin (not the one dirctly to pin 2) with the coupling cap = 470uf - 1000uf. I'm worried about the cap charging & discharging. This would hopefully allow me to keep my pre DC coupled (the way it is now) when the OT is used & add the cap when OT is bypassed... I HOPE :green:
Kevin
I just realized you answered my first question earlier in the thread... sorry.
I think my question should have been, is there a preferred cap type in these positions?
The pre sounds very good but each channel has a slightly different shape & character... some better than others. I'm not sure where to begin looking for the differences to get the 2-3 weaker channels up to par :? It's not that they're bad, a few are just a little cloudy & less punchy than the others.
What component(s) do you think have the highest impact on the sound?
The OP-AMP???
I have a few extras of every thing.
Also, when dealing with the feedback cap...
Does the "High End" increase as the caps value goes down?
I ask this because I'm using 47pf Ceramics I pulled from the old board a wondered if some cound be out of spec... I did check them with my volt meters capacitance test setting but I'm sure it's not telling me everything.
This is why I'm asking about the caps... I'm going to place an order for some parts.
Thanks for helping,
Kevin
BTW Fred,
That output drawing looks good & makes sense but I'd like to use ONE output (XLR) for both choices...
Here is the switch I used for my PM2000 to Bypass the Output Tranny BUT an output coupling cap is in the circuit for BOTH positions, just before the switch.(not shown in pic)
I was thinking to use this switch but replace the GREEN wire on TOP Right going from pin to pin (not the one dirctly to pin 2) with the coupling cap = 470uf - 1000uf. I'm worried about the cap charging & discharging. This would hopefully allow me to keep my pre DC coupled (the way it is now) when the OT is used & add the cap when OT is bypassed... I HOPE :green:
Kevin
rafafredd
Well-known member
Argh. Sorry i don´t even wanna look at this (drawing schem would be better). Anyway, should be simpler than what you got, with only three poles:
If your unbal loads are always 10k or higher, you probably could go OK with only two poles:
I like one pole and two connectors for my preamps. I don´t like unbal signals on XLR.
If your unbal loads are always 10k or higher, you probably could go OK with only two poles:
I like one pole and two connectors for my preamps. I don´t like unbal signals on XLR.
khstudio
Well-known member
Hey thanks for taking the time to draw that :thumb:
I know... it's hard to look @ my layout pic.
I like #1.
I usually don't connect pin 1 on my pre outputs but...
I guess floating the cap on the output, when not being used, won't hurt anything & it makes things easier... Should i worry about discharging it in ANY of these configuration?
Also, if you or anyone could help with the few final questions I had in the last post would be killer :green: I'm hating the thought of digging around & ripping this thing apart trying to fix the few (slightly under par) channels...
What do you think I should check first?
They all measured almost exact with RMAA but that's not real life with dynamics... I can say this, when I first fired it up I sat with an SM58 in hand & listened to ALL the channels - my least favorite channels were #1 = Bass Drum channel & #8 = Overhead right... & they were the same 2 channels that didn't perform as well as the others.
I can slightly discribe it...
The ones that felt "right" seemed to pull my voice out of the mic, have a balanced tone & nice dynamics.
The others I felt I had to push my voice more to get it to cut & lacked a little tone & dynamics (cut).
Kevin
I know... it's hard to look @ my layout pic.
I like #1.
I usually don't connect pin 1 on my pre outputs but...
I guess floating the cap on the output, when not being used, won't hurt anything & it makes things easier... Should i worry about discharging it in ANY of these configuration?
Also, if you or anyone could help with the few final questions I had in the last post would be killer :green: I'm hating the thought of digging around & ripping this thing apart trying to fix the few (slightly under par) channels...
What do you think I should check first?
They all measured almost exact with RMAA but that's not real life with dynamics... I can say this, when I first fired it up I sat with an SM58 in hand & listened to ALL the channels - my least favorite channels were #1 = Bass Drum channel & #8 = Overhead right... & they were the same 2 channels that didn't perform as well as the others.
I can slightly discribe it...
The ones that felt "right" seemed to pull my voice out of the mic, have a balanced tone & nice dynamics.
The others I felt I had to push my voice more to get it to cut & lacked a little tone & dynamics (cut).
Kevin
rafafredd
Well-known member
could be the old transformers, I don´t know. Could also be the amount of DC on the output transformers. Try measuring and see if there´s any relation.
mattmoogus
Well-known member
How can you possibly tell those differences by listening as you talk into a mic? If theres no difference showing up with RMAA Id be testing by running the same recording thru each pre in turn. Ideally you need to do this blind as its so so easy to fool yourself if youre listening for something you think is there. We do it every day in the workshop.
M@
M@
khstudio
Well-known member
[quote author="rafafredd"]could be the old transformers, I don´t know. Could also be the amount of DC on the output transformers. Try measuring and see if there´s any relation.[/quote]
I forgot to mention... this was one of the 1st things I did.
It did NOT seem to have any relation
k
I forgot to mention... this was one of the 1st things I did.
It did NOT seem to have any relation
k
khstudio
Well-known member
[quote author="mattmoogus"]How can you possibly tell those differences by listening as you talk into a mic? If theres no difference showing up with RMAA Id be testing by running the same recording thru each pre in turn. Ideally you need to do this blind as its so so easy to fool yourself if youre listening for something you think is there. We do it every day in the workshop.
M@[/quote]
Well, I can & did here a difference.
I'm not sure I was totaly clear but I mic'd up & tracked drums thru this thing so I could make a comparison to my M80 I had been using for years.
Not moving the mics around between testing & playing very similar beats, toms & cym's on each...also, getting the levels VERY close.
I listened several different times with hours &/or days in between, also using different speakers & soloing kick against kick, snare against snare, etc...
Then my friend & myself both separatly listened to each channel & had very similar opinions.
All this before posting here!!!!!!!!
I was thinking of running samples or music thru each to be more fair but that's "program music", not very dynamic from a live instrument, un-EQ'd & with a mic.
I didn't make my final choice with the mic in hand... I just noticed that what I tracked on those channels (I didn't like as much with the mic) weren't as good also with the drums... doesn't seem that unorthodox to me :?
k
M@[/quote]
Well, I can & did here a difference.
I'm not sure I was totaly clear but I mic'd up & tracked drums thru this thing so I could make a comparison to my M80 I had been using for years.
Not moving the mics around between testing & playing very similar beats, toms & cym's on each...also, getting the levels VERY close.
I listened several different times with hours &/or days in between, also using different speakers & soloing kick against kick, snare against snare, etc...
Then my friend & myself both separatly listened to each channel & had very similar opinions.
All this before posting here!!!!!!!!
I was thinking of running samples or music thru each to be more fair but that's "program music", not very dynamic from a live instrument, un-EQ'd & with a mic.
I didn't make my final choice with the mic in hand... I just noticed that what I tracked on those channels (I didn't like as much with the mic) weren't as good also with the drums... doesn't seem that unorthodox to me :?
k
khstudio
Well-known member
[quote author="raysolinski"]I have a yamaha op amp on the way and I am dropping it in an api 312 card...could I ask you what values you used for the resistor, cap and pot in the feedback loop? I saw you made a bunch of these a while back..
Cheers,
Ray[/quote]
Cheers,
Ray[/quote]
raysolinski
Well-known member
Well I got the 80200 parked in an API 312...+/- 24 volt rails...It is really nice!
A different flavor than thr Hardy or Forssell for sure..I would say it is in between a JH990 and a 25*20..not quite as detailed or bright as the JH.. a little more low end but not muddy at all. Very low noise floor for a vintage unit....I wasn't sure if it could push a 75 ohm load so I used a UTC A24 matching tranny for the output...A good crayon for the box..If you see one of these guys floating around, grab it! You won't be disapointed :thumb:
Cheers,
Ray
A different flavor than thr Hardy or Forssell for sure..I would say it is in between a JH990 and a 25*20..not quite as detailed or bright as the JH.. a little more low end but not muddy at all. Very low noise floor for a vintage unit....I wasn't sure if it could push a 75 ohm load so I used a UTC A24 matching tranny for the output...A good crayon for the box..If you see one of these guys floating around, grab it! You won't be disapointed :thumb:
Cheers,
Ray
khstudio
Well-known member
[quote author="raysolinski"]Well I got the 80200 parked in an API 312...+/- 24 volt rails...It is really nice!
A different flavor than thr Hardy or Forssell for sure..I would say it is in between a JH990 and a 25*20..not quite as detailed or bright as the JH.. a little more low end but not muddy at all. Very low noise floor for a vintage unit....I wasn't sure if it could push a 75 ohm load so I used a UTC A24 matching tranny for the output...A good crayon for the box..If you see one of these guys floating around, grab it! You won't be disapointed :thumb:
Cheers,
Ray[/quote]
Very cool man thanks for sharing:thumb:
I've been using the 8 channel API/YAM pre I built for about a month now & it is KILLER :green: My drums never sounded so real... it's smooth, FAT, airy & punchy & the 24 volt rails just seem to help it breath.
Kevin
A different flavor than thr Hardy or Forssell for sure..I would say it is in between a JH990 and a 25*20..not quite as detailed or bright as the JH.. a little more low end but not muddy at all. Very low noise floor for a vintage unit....I wasn't sure if it could push a 75 ohm load so I used a UTC A24 matching tranny for the output...A good crayon for the box..If you see one of these guys floating around, grab it! You won't be disapointed :thumb:
Cheers,
Ray[/quote]
Very cool man thanks for sharing:thumb:
I've been using the 8 channel API/YAM pre I built for about a month now & it is KILLER :green: My drums never sounded so real... it's smooth, FAT, airy & punchy & the 24 volt rails just seem to help it breath.
Kevin
khstudio
Well-known member
Had some PM's about my missing pics... FIXED!
Humner
Well-known member
I know this thread is very old, but it covers exactly what I want to do. However alot of the pictures are gone.
If anyone has some of the picture files, or the PCB layout or the schematic for mic pre based on NE80100.
It really just needs to be a very simple circuit. It will form the input section and then go to a summing channel of a PM700(which is a discrete EQ section to a NE80100 then output transformer).
If anyone has some of the picture files, or the PCB layout or the schematic for mic pre based on NE80100.
It really just needs to be a very simple circuit. It will form the input section and then go to a summing channel of a PM700(which is a discrete EQ section to a NE80100 then output transformer).
EvLoutonian
Well-known member
- Joined
- Jul 8, 2010
- Messages
- 198
Great job - also in admiration of this eloquently executed racking effort.
I realize this is a very old thread, but I am looking to do a similar build. I searched but could not find a complete parts list. I did find the Mitsos BOM, but it would appear his build is different. Basically I need a BOM for this build, so if you are out there, khstudio, any help would be appreciated.
